Mendelian Transmission of Alleles

Question 1

if we know the genotypes of two parents we can…

Answer 1

predict the genotype of their offspring

Question 2

a cross btw 2 homozygotes always gives…

Answer 2

a heterozygote

Question 3

a cross between diploids where all 4 alleles in the parents are different…

Answer 3

4 possible combinations all with equal frequencies

Question 4

a cross of 2 heterozygoes Aa x Aa genotypes

Answer 4

genotype AA 1/4

Aa 1/2

aa 1/4

ratio is 1:2:1

Question 5

a cross of 2 heterozygotes Aa x Aa phenotypes

Answer 5

AA + Aa 3/4

aa 1/4

ratio is 3:1

Question 6

mendelian ratio

Answer 6

a cross btw 2 heterozygoes yields ratios

genotypic: 1:2:1
phenotypic: 3:1

Question 7

mendel worked with ___ which are normally ____

Answer 7

peas, self-fertilizing

Question 8

how to cross peas

Answer 8

cut open flower before sex parts are mature

transfer pollen from one flower to another

put pollen on the pistil (gateway to female gamete)

Question 9

pollen is the ___ gamete

Answer 9

male

Question 10

mendel’s question

Answer 10

what happens when you cross two distinct true-breeding strains?

Question 11

mendel first…

Answer 11

crossed pairs of strains with distinct alternative traits

purple x white flowers

Question 12

first thing mendel noticed

Answer 12

in every cross, one was dominant

Question 13

mendel secondly…

Answer 13

allowed hybrids to self-fertilize

Question 14

mendel noticed secondly…

Answer 14

offspring of 2nd generation showed both traits again

ratio of 3:1 dominant:recssive

Question 15

particulate inheritance

Answer 15

information is copied and passed on in some physical form

Question 16

diploidy

Answer 16

individuals have 2 copies of the info for each trait

one from each parent

Question 17

dominance/recessivity

Answer 17

some copies only produce their effect when the other copy is absent

Question 18

random segregation

Answer 18

2 copies for each trait are passed on independently and randomly

Question 19

mendel’s 1st law

Answer 19

segregation

alleles of genes are copied and passed on independently through haploid and diploid phases

Question 20

phenotypic ratio of 3:1 results from…

Answer 20

cross of 2 heterozygotes if there is dominance

Question 21

phenotypic ratio of 1:1 results from…

Answer 21

cross of a heterozygote with a recessive homozygote

Question 22

phenotypic ratio of 2:1 results from…

Answer 22

crossed heterozygotes if a dominant allele is recessive lethal

Question 23

in offspring with a 3:1 phenotypic ratio….

Answer 23

2/3 of the dominant types are carriers (heterozygotes)

Question 24

genotypic ratio of 1:2:1 at conception…

Answer 24

result from a cross of 2 heterozygotes

Question 25

achondroplastic dwarfism

Answer 25

cross heterozygotes Dd x Dd

genotypic ratio at conception 1:2:1

phenotypic ratio at birth 2:1 (DD babies die)

dd gives normal height

Question 26

mexican hairless dogs

Answer 26

all are heterozygotes

cross Hh x Hh

genotypic ratio at conception 1:2:1

phenotypic ratio at birth 2:1 (HH babies die)

hh gives dog with hair